A comparative canine-human therapeutics model is being developed in B-cell lymphoma through the generation of a hybridoma cell that produces a murine monoclonal antibody specific for canine CD20. The hybridoma cell produces two light chains, light chain-3, and light chain-7. However, the contribution of either light chain to the authentic full-length hybridoma derived IgG is undefined. Mass spectrometry was used to identify only one of the two light chains, light chain-7, as predominating in the full-length IgG. Gene synthesis created a recombinant murine-canine chimeric monoclonal antibody expressing light chain-7 that reconstituted the IgG binding to CD20. Using light chain-7 as a reference sequence, hydrogen deuterium exchange mass spectrometry was used to identify the dominant CDR region implicated in CD20 antigen binding. Early in the deuteration reaction, the CD20 antigen suppressed deuteration at CDR3 (VH). In later time points, deuterium suppression occurred at CDR2 (VH) and CDR2 (VL), with the maintenance of the CDR3 (VH) interaction. These data suggest that CDR3 (VH) functions as the dominant antigen docking motif and that antibody aggregation is induced at later time points after antigen binding. These approaches define a methodology for fine mapping of CDR contacts using nested enzymatic reactions and hydrogen deuterium exchange mass spectrometry. These data support the further development of an engineered, synthetic canine-murine monoclonal antibody, focused on CDR3 (VH), for use as a canine lymphoma therapeutic that mimics the human-murine chimeric anti-CD20 antibody Rituximab.

• Klíčová slova
• CD20, comparative medicine, hydrogen deuterium exchange mass spectrometry, lymphoma, monoclonal antibody,
• MeSH
• antigeny CD20 imunologie   MeSH
• chromatografie kapalinová MeSH
• imunoglobulin G chemie   MeSH
• kinetika MeSH
• lehké řetězce imunoglobulinů genetika   metabolismus   MeSH
• lidé MeSH
• monoklonální protilátky chemie   genetika   MeSH
• nádorové buněčné linie MeSH
• peptidová knihovna MeSH
• psi MeSH
• rekombinantní fúzní proteiny MeSH
• sekvence aminokyselin MeSH
• tandemová hmotnostní spektrometrie MeSH
• těžké řetězce imunoglobulinů genetika   metabolismus   MeSH
• vazebná místa protilátek MeSH
• vodík/deuteriová výměna a hmotnostní spektrometrie * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antigeny CD20 MeSH
• imunoglobulin G MeSH
• lehké řetězce imunoglobulinů MeSH
• monoklonální protilátky MeSH
• peptidová knihovna MeSH
• rekombinantní fúzní proteiny MeSH
• těžké řetězce imunoglobulinů MeSH